Write a C program to print the given number pattern using for loop. How to print the given triangular number pattern using loop in C programming. Logic to print the given number pattern using C program.

## Required knowledge

## Logic to print the given number pattern

To get the logic of the pattern have a close look to the pattern for a minute. You might notice following things about the pattern.

- It contains N rows (where N is the total number of rows to be printed).
- Each row contains exactly i columns (where i is the current row number).
- For all odd rows it contains numbers in increasing order from 1 to i. Hence the inner loop formation to print the odd rows will be for(j=1; j<=i; j++).
- For all even rows it contains numbers in decreasing order from i to 1. The inner loop formation to print the even rows will be for(j=i; j>=1; j–).

Based on the above observations lets code down the solution of the pattern.

## Program to print the given number pattern

```
/**
* C program to print the given number pattern
*/
#include <stdio.h>
int main()
{
int i, j, N;
printf("Enter rows: ");
scanf("%d", &N);
for(i=1; i<=N; i++)
{
if(i & 1)
{
// Print numbers for odd row
for(j=1; j<=i; j++)
{
printf("%d", j);
}
}
else
{
// Print numbers for even row
for(j=i; j>=1; j--)
{
printf("%d", j);
}
}
printf("\n");
}
return 0;
}
```

Output

Enter rows: 5 1 21 123 4321 12345

Happy coding ðŸ˜‰